1. Field of the Invention
The present invention relates generally to window covering installations, more particularly to arched window coverings, and, still more specifically to fasteners used to secure the outer edge of arched shade material.
2. Description of the Related Art
Arched windows are often used to provide decorative interest and architectural detail in buildings of all types. In some instances, it is desirable to provide a window covering over the arched opening to control light entering through the window or to provide privacy. Window coverings also can add an additional level of decorative detail.
Many different types of window coverings have been used in arched openings. It is known to provide a mounting rail along the horizontal surface of the arched opening, which often will be at the bottom of the arched opening. The shade material than extends outwardly from the bottom rail and may or may not be movable. In some situations it is desirable to secure the curved outer edge of the shade material to the window opening along the entire edge in a channel or other arched holder retaining the fabric and mounted in the window opening. It is known also to use discrete fasteners at several spaced locations along the edge of the material, or at least a single fastener in the center of the fabric and window opening.
It is known to use a one-piece fastener that is secured to the outer edge of the window covering fabric and then screwed or otherwise fastened to the window frame during installation. Such installations have been difficult to complete in that the installer must first locate the center of the arched material so that one fastener can be secured at the center of the material and the center of the opening. Additional fasteners can be added at spaced locations along the edge. This requires accurately measuring the curved peripheral edge of the window covering material or counting the pleats in pleated material or cells in so-called cellular window covering material, and then completing attachment to the material and to an accurately determined window location. Failure to locate the correctly corresponding locations on the material and the window frame can result in an unbalanced appearance of the shade material in the window opening, often requiring redoing the attachment.
Known fasteners have used aggressive frictional engagements with the fabric material and/or adhesive attachment, each of which have resulted in damage to the fabric material in some instances as the fastener is being attached. Further, if it becomes necessary to move the fastener, perhaps because it was secured in a wrong location initially, removing the fastener from the material can be difficult and may result in unacceptable visible damage to the fabric material. Still further, the use of a one-piece clip is awkward in that, if the clip is first fastened to the shade material, securing the clip by screws or the like in the window frame can be difficult as the shade material interferes with access. Alternatively, if the fastener is first screwed into the window frame, inserting the fabric into the frictional engagement portion of the fastener can be difficult because of the limited space available. Again the cumbersome techniques required for attaching the one-piece fastener to both the shade material and the window opening can result in damage to the shade and/or soiling of the shade due to the manual manipulation required.
What is needed is a fastening system useful on shades of all types, but particularly useful for arched shades, having separate components that can be secured to the window and to the shade material separately and thereafter brought together to hold the shade material as desired. A simplified structure for securing the clip to the shade material is desirable, preferably one that can be attached, detached and reattached in the same or different locations without perceptible damage to the shade material.